I can no longer move the render window camera, nor can I move things in the render window.
I've tried restarting it, reinstalling it, but for some reason it just will not work.
Makes modding very hard.

Have I messed up a setting somewhere or is this a genuine glitch?

Not sure how you managed to get it to glitch like that

However, try deleting ConstructionSet.ini from your ...My Games\Oblivion folder, and then re-launching.

It should reset the layout of your cs and your render window camera will hopefully work.

You're a clever one. :bowdown:
I was playing with the "biped object" options with a suit of armor and I think that caused it.
Your fix solved the problem.
Thanks! :biggrin: